Dipole antenna construction



Jan. H7, 1956 J. R. MARSHALL DIPOLE ANTENNA CONSTRUCTION Filed Aug. 9, 1946 2 Shets-Sheet 1 N I I/ w m N N g LL INVENTOR. JAMES R. MARSHALL Jam. 17, H5O

Filed Aug. 9, 1 946 J. R. MARSHALL 2 Sheets-Sheet 2 2 m 9' LI...

a E l I o I INVENTOR. JAMES R. MARSHALL Patented Jan. 17, 1950 UNlTED STATES G'FF-liCE DIPOLE. anrsnfiit ns'mucriou James R; Marshall, Englewood, Nz'Ji', assignor'to Dielectric Produets company; Inc-.,- Jersey City-,-

ApplicaticnAugustB, 1946 erialJNol 689,420;

10 Claims. (Cl. 250-3 3 This invention relatesto, a fornr of" antenna especially adapted for use, in television recep: tion.

The principal object'of my invention isto provide an antenna, construction. which is fundamentally a broad band half 'wave dipole with at least one modifying element projecting from the innermost end of each element for the purpose of altering the field pattern of theantenna when it is being usedas a receiving antenna for the channels in theupper' television band, 174' to 216 me.

A further object of my invention is-to eliminate undesirable-side lobesin the horizontal raw diation pattern whenjthe antenna ,is'being used to receive signals in the ,upper-TV'band.

A further object-of my-invention is tohave the antenna maintain the characteristics of "a half wave dipole throughout the-lower television band; and by the use of modifying elements attached to the inner ends of the dipole elements; and projecting obliquely to the plane of the dipole, to; alter the field pattern of the-halfwave dipole when it is inuse in theupper television band so; that the antenna will be directive toward the front the same as--itis'inthe-lower television band.

A further object of my invention-is to provide an antenna constructionin which the previously mentioned obj sets may be obtained; in a relatively simple and inexpensivemanner.

My improved type of antenna construction; is shown-in the attached drawings-wherein-,

Figure 1 isafrontelevation-of the-structure;

Figure 2 is a plan view of-the-structureshown in- Figure 1.

Figure 3- is a section ontheline 3'3ofFig ure 1.

Figure 4 is a-section on-the line 4 '--4 o;f-Figure- 1';

Figure 5 is asection on-theline-5 -5-of-Figure1';

Figure-6 is-a-schematie view-of the radiation field pattern in a horizontal plane containing the antenna elements-whenthe main elements form a dipole of-one-half wavelength andwhen the modifying el'ements are not used.

Figure 7 illustrates a pattern taken from thesamedipole antenna asfrom which the pattern of FigureG has been takenbut when the frequency has been increased, or the wavelength has been decreased, to a point; where the main; elements of the antenna, formoa dipole off'three halves wave length long,

Figure, 8 is a. view similar. to Figurelbut'illusr trating the condition: when the frequency has been increased'to the point where: the m ain,ele '-v any satisfactory means as;-b-y screw studs, lock merits ofl the antenna form a dipole of'two wave len ths s-s Figure 9oisva dia fam illustrating the. radiation fieldipattern off'the antenna irra horizontal? plane containing the. elements atthe condition shown in Figures l andswhen the modified eleiments of my improved constructions'are utilized;

Referring now to the-detailswherein like numbers refer to corresponding parts, I is'astandardforsupporting the various-parts; of the antenna: The standard I is preferably made out oftubing; the upper end of" which is-fiattened at 2 andon this flat portionis mounted a pair-of insulators; 3 and ti of suitable material, these insulators being ,f'astened to the part- 2- of the standard by Washers and nuts generally'referred to bythe number 5. The main part of thed-ipole antenna comprises two sections, 6 and! which are pref erably made oftubing-of suitable metal such as aluminum or copper. The section 6' hasbase portions 8 and 8 which telescopically receive the two arms of sections; The-sections 8 and 8 are alike sov the descriptionof one will'do for-both. The portion 8- is fastened to--the-insulator-3- as illustrated in Figure 5 by means of r a slotted clamp 9 which'engagesa reenforcing'sleeve 24 that is fastened to the insulator 3 by-screw stud I01 Theclamp ahas aprojection with a-slot l2} therein to receive-a clamping studl3 positioned in theend M of one end ofthe-section 15 of one of themodifying members. The section l5'-'may be telescopically mountedin its cooperative part l4 and terminates in a fiat end [6 which is welded or riveted'to a cooperative frame portion 16 of section l5 that may be telescopiing memberM'j shown in the left hand portion of Figurel is-similar in constructionin its mounting as M ,and'acts'gto modify the radiatingfield actionofthe dipole section-Fin the same manner as the-modifier M acts in connection withthe dipole section 1;

Figures'B and'4 show the connections made with respect to the main antenna sections; con: taining elements 6 andl8. It is seen by reference to Figure l'that the insulator. ,3',ha s,a ,recess l1 therein. Positionelil11inthis. recess,ls,,a screw 3 [8 which passes through the section 8 of the antenna as well as through a stiffening member 19 that may be of wood and extends outwardly even into the arm of the antenna. The screw [8 also passes through and is fastened to a connecting strap 2% that goes across and connects to the opposite arm of the antenna 6 as illustrated in Figures 1 and 3. An electrical conductor 2| is fastened to the bar 20 at its center, in any satisfactory manner as by screw stud and associated parts 22. This conductor 2|, which is preferably insulated, is supported by an insulator 23 that is In order to clarify the following paragraphs,

Figures 6, 7, 8 and 9 represent a polar plot of the radio frequency voltage produced across the terminals of the antenna as a function of rotation of the antenna, in degrees, in the plane of the elements when the antenna elements lie'in the plane perpendicular to the electromagnetic flux lines of the polarized field of the transmitting signal, referred to as a horizontal plane in present television practice.

It will be seen from Figure 2 that the supplemental antenna section M, and M which I referred to as modifiers have an arcuate movement as well as individual close fitting telescopic action between the parts. By reason of this construction I am able to adjust these modifiers so as to produce a variety of effects, one being the results depicted diagrammatically in Figure 9 wherein the objectionable features illustrated by the lobes 25, 26, 21, 28 and 29 in Figure 7 and all of the similar lobes: in Figure 8 are eliminated.

It is then possible by this mechanical and electrical design to control the magnitude and electrical phase relationship of any induced radio frequency currents fiowing in the elements of the above-described antenna by mechanical movement of the elements so as to produce current flow in the elements that are orientated in the field of the transmitted radio frequency signal as indicated by Figure 9.

As previously stated this above modification applies only at the condition when the main elements are one and one-half or two wave lengths long as described with respect to Figures '7 and 8. It does not disturb its function as a half-wave dipole described in Figure 6.

Havin thus described my invention, what I claim is:

1. A dipole antenna construction including a support, a pair of U-shaped members, comprising the main part of the antenna, insulatingly mounted on the support with the arms of the Us projecting toward each other in substantially the same alignment and plane, the extremities of each U member being electrically connected together by a metallic member of very low impedance, the said members having means for making an electrical connection thereto midway between said U extremities and means comprising modifying elements directly connected to the inner ends of each of the said main parts and projecting therefrom in opposite directions to said parts to which they are connected for eliminating undesirable lobes in the horizontal radiation pattern of the antenna when certain undesirable radio waves encounter said main parts of the antenna construction.

2. A dipole antenna construction as set forth 4 in claim 1 further defined in that said second mentioned means comprises two modifying devices, one for each of the main parts of the antenna, each of said devices havin spaced arms at least electrically connected to the arm of its associated main antenna part, said spaced arms converging to a junction and anchored together thereat.

3. A dipole antenna construction as set forth in claim 1 further defined in that said second mentioned means comprises two modifying devices, one for each of the main parts of the antenna, each of said devices having spaced arms ,mechanically and electrically connected to the corresponding arms of its associated main antenna part, ,thearms being laterally spaced from and extending at an angle with the arms of the main antenna parts and converging to a junction and anchored together thereat.

4. A dipole antenna construction as set forth in claim 1 further defined in that said second mentioned means comprises two modifying devices, one for each of the main parts of the antenna, each of said devices having spaced arms at least electrically connected to the arm of its associated main antenna part, the arms having adjustable sections and being laterally spaced from the arms of the main antenna parts and extending at an adjustable angle with respect thereto, the two arms of each device converging to a junction and anchored together thereat.

5. A dipole antenna construction including a support, a pair of U-shaped members, comprising the main part of the antenna, insulatingly v the inner ends of the main dipole elements and projecting therefrom obliquely to the plane of said main elements for eliminating undesirable lobes in the horizontal radiation pattern of the antenna when the frequencies of the signals being received are outside the band of frequencies for which the main elements of the antenna were designed.

6. A dipole antenna construction as set forth in claim 5 further defined in that said second mentioned means includes a modifying device for each main antenna part, each of said devices having a pair of spaced arms, one end of which is pivotally and slidably mounted and at least electrically connected to the arms of their associated main antenna parts, the arms converging to a junction and anchored together thereat.

7. A dipole antenna construction including a support, a pair of U shaped members, comprising the main part of the antenna, insulatingly mounted on the support with the arms of the Us projecting toward each other in substantially the same alignment and plane, the extremities of each U member being electrically connected together by a metallic member of very low impedance, the said members having means for making an electrical connection thereto midway between said U extremities, and modifying means comprising mechanical devices connected to the ends of the U members preferably adjustably mounted and so formed and connected as described to control the magnitude and phase relationship of any induced radio frequency currents flowing in the main antenna parts whereby objectionable features as illustrated and described are eliminated.

' 8. A dipole antenna construction including a support, insulating means carried by the support, the two members of the dipole being fastened to said insulating means and means comprising U- shaped modifier elements directly connected to the adjacent ends of the dipole members and projecting in front of the plane of said dipole members for eliminating undesirable side lobes in the horizontal radiation field pattern of the antenna when radio waves of a frequency higher than that for which the main members are designed, encounter the antenna.

9. A dipole antenna construction as set forth in claim 8 further characterized in that each modifier element consists of at least one arm connected to an inner end of one of the main members and extending therefrom in front of the other main member.

10. A dipole antenna construction comprising a pair of U-shaped tubular electrical conducting REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,069,513 Wolff Feb. 2, 1937 2,213,276 Gossel Sept. 3, 1940 2,283,914 Carter May 26, 1942 2,299,218 Fener Oct. 20, 1942 2,430,353 Masters Nov. 4, 1947 

